1. Filed of the Invention
The present invention relates to a composite writing instrument comprising a plurality of writing means at least one of which is a ball-point pen refill equipped with a tip portion of a ball-point pen at the tip and an ink reservoir section at a rear end, so that writing tip portions may selectively be allowed to protrude from a body end, and pumping type pressurization operation may help an ink to flow towards the tip side of the above-mentioned ball-point pen.
2. Description of the Related Art
Examples of a composite writing instrument in which a plurality of writing means are mounted, and writing tip portions are selectively allowed to protrude from a body end, and a writing instrument in which pumping type pressurization operation helps an ink to flow towards the tip side of the above-mentioned ball-point pen, are described in Japanese Laid Open Patent No. 2001-205980 (Patent Document 1), Japanese Laid Open Patent No. 2000-62387 (Patent Document 2), Japanese Laid Open Utility Model No. H01-161081 (Patent Document 3), Japanese Laid Open Patent No. H08-52407 (Patent Document 4), International Publication No. H07-506862 (Japanese Translation of PCT International Application) (Patent Document 5), Japanese Laid Open Patent No. 2001-150865 (Patent Document 6), Japanese Laid Open Patent No. 2001-171286 (Patent Document 7), and Japanese Laid Open Utility Model S63-98776 (Patent Document 8).
Each of the related art documents will be briefly described hereafter.
(Patent Document 1)
It proposes a ball-point pen using an ink which tends to be disrupted in initial writing, and a knock type writing instrument which carries a refill of the ball-point pen allowing correction of a clerical error etc. mainly by concealing it with a white ink.
Those that are proposed in this document can be provided cheaply in terms of costs. However, when a pressurization cylinder is operated to retreat from an advanced state, the inside of the pressurization cylinder tends to be depressurized, so that the ink is urged to flow backwards, whereby there is a disadvantage that recovery of the ink or pressurization performance may be impaired.
Moreover, only one writing means is mounted which consists of a refill for one ball-point. It is not taken into consideration the case where the writing means which consists of a plurality of refills of ball-point pens.
(Patent Document 2)
A plurality of ball-point pen writing means are mounted at least one of which employs an oil-based ink having a low viscosity. When each knock body is knocked, an engagement projection is held in engagement with an engagement step portion at a clip top, thus leaving a writing tip portion to project.
A knock type composite writing instrument is known in which the engagement is released when the clip is put on a breast pocket in the above state, and which is provided with a security mechanism such that a writing tip portion may be retracted into the instrument body.
(Patent Document 3)
A composite writing instrument (multiple type writing instrument) is proposed which is characterized in that a plurality of writing means are mounted, a knock portion is formed to protrude from a rear end of a cap, a rotor (rotating projection member) located at a front side of the knock bar is rotated by knocking a knock bar so as to rotate a cylindrical cam of the cap and advance or retreat and locate the cylindrical cam, and in conjunction with this a writing tip portion is allowed to project or retract through a top end hole of an front body.
(Patent Document 4)
Conventionally, in order to correct a clerical error etc., a liquid applicator using a white pigment is known. Further, since the white pigment and a solvent tend to separate, this type of liquid applicator encloses an ink, a ball, etc. in a flexible container. It is necessary to shake and agitate them when in use. Further, in order to discharge the ink, a side of the container is pressed. However, this is irritating because the ink is not discharged even if a side wall of the container is pushed strongly, when the ink residual quantity decreases.
(Patent Document 5)
A writing instrument is known which uses an ink having a shear thinning viscosity with no need for agitation, however, there is a problem that the ink flows backwards and tends to run out when it is applied upwards.
(Patent Document 6)
A writing instrument is proposed in which a pumping type pressurization mechanism portion is provided in the rear end of a body cylinder, further in the front thereof a follower is disposed in contact with the rear end of the ink so as to follow the ink consumption, and a valve system is disposed in the rear end of the follower, air is pressed and supplied through a rear end hole of the body cylinder by way of advancing operation of the pressurization mechanism portion, during which the valve is opened at a predetermined pressure so that the rear end of the follower is pressurized, to thereby support the ink flow towards the tip side.
However, there is a problem with this writing instrument in that a proper pressure cannot be set up because of deviations in the valve mechanisms (deviations in springs which act on opening and closing the valves, dimensional deviations in rubber-made valves which elastically open and close slits, etc.).
Further, there is a problem that when a ball-point pen is not in use and when the pressure exceeds a predetermined setup value, an external force is improperly applied to a writing tip portion so that the ink bleeds.
Moreover, only a writing means consisting of a refill is mounted, so that it is not taken into consideration the case where the writing means including refills of a plurality of ball-point pens is mounted.
(Patent Document 7)
A knock type writing instrument is proposed in which a pressurization mechanism portion is mounted.
However, similar to the above-mentioned Patent Document 6, there is a problem that a proper pressure cannot be set up for this one because of deviations in valve mechanisms (deviations in springs which act on opening and closing valves, dimensional deviations in rubber-made valves which elastically open and close slits, etc.).
Further, there is a problem that when a ball-point pen is not in use and when the pressure exceeds a predetermined setup value, an external force is improperly applied to a writing tip portion so that the ink bleeds.
Moreover, only a writing means consisting of a refill is mounted, so that it is not taken into consideration the case where the writing means including refills of a plurality of ball-point pens is mounted.
(Patent Document 8)
A writing instrument is proposed in which a pressurization mechanism is provided in the rear end so as to help ink flow by way of pumping operation and prevent the ink from flowing backwards.
Further, only one writing means is mounted and it is not taken into consideration the case where a plurality of writing means are mounted.